Synthetic fiber materials for use in automotive interior materials are required for having a high temperature resistance and a high light resistance because automotive interiors reach high temperature and high humidity and the synthetic fiber materials are exposed to sunlight over a much longer time than other common clothing fiber materials. In order to meet such a requirement, a method is adopted in which dyes having a high light resistance are used to dye fibers. However, if a yellow dye, a red dye and a blue dye are not in balance of light resistance, only a part of colors is faded due to a long period of light exposure, easily resulting in that discoloration of these dyes as a whole gradually appears larger over time. Therefore, a yellow dye, a red dye and a blue dye to be used are required for achieving a balanced light resistance so that these colors are equally faded, but no dyes have been obtained which satisfy such a requirement.
In addition, the synthetic fiber materials achieve a different depth of dyeing, different dyeing shade, and the like from one another even by the same dyeing method, due to the differences in yarn thickness and yarn shape as well as the difference of blended fibers or the like in which a polyester fiber to be used is blended with other material. In order to dye and process such synthetic fiber materials having a different shape and different properties equally each time, there is a need for dyes excellent in dyeing reproducibility even under various dyeing conditions.
In particular, when automotive interior materials are dyed, dyeing is performed with the use of disperse dyes having a high fastness to environmental conditions as much as possible. However, if a yellow dye, a red dye and a blue dye are not even with one another in terms of dyeing properties, such unevenness causes the difference in dyeing reproducibility among synthetic fiber materials dyed. Accordingly, in order to dye automotive interior materials, there are needs for high light fastness of each colors of a yellow dye, a red dye and a blue dye, which are also in balance with one another, as well as for even dyeing characteristics and a favorable dyeing reproducibility.
Although various disperse dye compositions have been disclosed in Patent Literatures 1 to 3 etc. below, no dye compositions satisfying the above needs have not been described therein.